The domestic Taihang engine, the advancement of aero-engines largely depends on the advancement of materials
Recently, it has been reported that relevant Chinese units have successfully developed a new generation of titanium-aluminum alloy. This alloy can withstand a high temperature of about 900 degrees, can be used for domestic aero-engines, and effectively improve the performance of domestic aero-engines.
Titanium aluminum alloy has good flexibility, high material strength, and good creep resistance under high-temperature environments. Mainly used in aero-engine compressor blades and low-pressure turbines, the successful development of a new type of titanium-aluminum alloy has laid a solid foundation for domestic aero-engines to increase their thrust-to-weight ratio.
The progress of domestic materials provides a material basis for domestic aero-engine upgrades
As we all know, an aero-engine is a heat engine in principle. It uses thermal energy to heat the air, and the latter is heated and expanded to convert thermal energy into kinetic energy. Therefore, the energy of an aero-engine comes from the temperature difference between intake and exhaust. The latter is what we often call the (high-pressure) temperature before the turbine. Under the same technical conditions, the higher the temperature before the turbine, the greater the thrust of the engine. But this will cause a problem, that is, the temperature in front of the turbine increases, and the internal environment of the engine will also increase, which puts higher requirements on the engine components.
On the other hand, the aircraft engine is the most important system of the aircraft, and its weight directly determines the weight of the aircraft structure. According to relevant information, the aircraft engine may increase by 1 kg, and the aircraft structure may increase by about 2 kg. Therefore, the development trend of aero-engines is that the thrust is getting larger and the weight is getting lighter and lighter, and the specific performance is that the engine thrust-to-weight ratio is getting higher and higher. The thrust-to-weight ratio of modern aviation engines has exceeded 10 and is still increasing.
Aero-engine high-pressure compressor blades
At present, high-temperature alloys are widely used in aero-engine compressors and low-pressure turbines, which are nickel-based high-temperature alloys. It has high strength and corrosion resistance in the range of 600-1000 degrees, but the disadvantage is that the weight is relatively large, which increases the overall weight of the engine, and the increase in the overall weight of the engine will further increase the weight of the aircraft structure. And regional aviation engine technicians hope to use a new generation of high-temperature alloys instead of nickel-based alloys, which is a new generation of high-temperature-resistant titanium aluminum alloys.
Titanium-aluminum alloys have been used in aero engines before, but the early titanium-aluminum alloys will rapidly decline in all aspects after the working temperature exceeds 600 degrees, which cannot meet the needs of aero engine operation. Therefore, after the 1990s, developed countries have invested a lot of resources to increase the working temperature of the titanium-aluminum alloy. After hard work, a technological breakthrough has been achieved. The successful development of titanium-aluminum alloy with a working temperature of more than 900 degrees has become practical. For example, the new generation of passenger aircraft engine LEAP uses titanium-aluminum alloy blades. The weight of the new blades is 50% lower than the original nickel-based superalloy blades. It can be said that the effect is significant.
Domestic titanium-aluminum alloy integrated blade
Relevant Chinese units also attach great importance to the application of titanium and aluminum alloys in the field of aero-engines. In the 1990s, the working temperature of domestic titanium and aluminum alloys has increased to 550 degrees. In the new century, domestic titanium and aluminum alloys will continue to break the 600 degrees mark. The material industry generally believes that this indicator is the "thermal barrier temperature" of titanium-aluminum alloy. Under this temperature, the titanium-aluminum alloy has better performance in all aspects, but it deteriorates in various aspects beyond this temperature. In order to improve the performance of domestic aero-engines, relevant domestic units started to develop titanium-aluminum alloys with better temperature resistance. After hard work, relevant units broke through a series of technical difficulties and successfully developed titanium-aluminum alloys that can withstand high temperatures of 900 degrees. Some properties even It is even better than similar materials in developed countries. For example, its room temperature plasticity is 4.9% higher than 2% of American single crystal alloy materials. The birth of this new material also lays a solid foundation for domestic aero-engine technology upgrades.
Domestically-made aero engines are moving forward
As the tip of the modern industrial revolution, aero engines have concentrated the highest technological achievements in many technical fields. Therefore, the technological advancement of aero-engines requires long-term and extensive exploration and research. Therefore, technological advances in the fields of materials and technology in China are constantly pushing domestic aero-engines forward.
